BOSTON - Laurel Ranticelli considered driving 40 miles round-trip to take education classes at the University of Massachusetts campus in Amherst. Then she realized she could take the same courses from her computer at home and save on fuel costs.

"It's gotten out of hand, the gas prices," said Ranticelli, 50, who lives in Springfield. "It's $70 a week. That's pretty close to my groceries."

She joins a growing number of students trying to save gas money by enrolling in online classes. Online enrollment has been steadily growing for years, but college administrators say the jump in gas prices -- to more than $4 a gallon in most places -- has fueled a surge in students seeking classes without the cost of commuting.

Although most colleges do not track students' reasons for choosing online learning, many administrators cite a clear link with fuel prices.

John Bourne, director of the Sloan Consortium, an organization in Wellesley that studies online education, said he expects gas prices to bring about "a blended classroom -- half online, half in class."

At Villanova University, the engineering school has seen a 40 percent increase in online enrollment this summer -- even though summer enrollments typically stay flat.

"We've attributed it to the huge gas prices," said Sean O'Donnell, who runs the engineering school's distance-education program.

In many online classes, students log on at their convenience for coursework, which is done mostly through independent study. Students and professors interact through online chats, message boards and e-mail.

Other classes are more traditional, with a mix of students attending in person and online. On-campus students can speak to their online classmates using microphones, and students online can watch lectures through cameras.

Many of the new online students at Villanova live within driving distance of the Philadelphia-area campus. But high gas prices are compelling them to reconsider preconceptions about online learning.

"This has been the catalyst to push people to change their thinking about their education," O'Donnell said. "You can now learn anytime, anywhere, on your schedule. They're not degrading the quality of education because of gas prices."

An informal online poll at Victoria College in Texas showed 42 percent of students plan to take online classes because of fuel costs. As a result of the increased interest, the school is preparing to increase online class capacity.

Administrators do have some concerns, including preventing students from dropping out.

"Retention in online classes is lower," school spokeswoman Kimberly Haschke said.

Karen Stevens, an early childhood education professor at the University of Massachusetts, said increased demand for online classes is forcing instructors to overcome doubts about the system.

"They weren't sure it was good education," she said. "If they had their preference, they would teach live. But because of gas prices, that's not practical."